beh backend broken: writes temporary files into /

pitti, can you adjust the AppArmor configuration so that the beh wrapper backend works? The beh backend is for fine adjustment of the handling of errors of CUPS backends. See http://www.openprinting.org/beh.html. beh is part of the foomatic-filters package.

After that happens, can you please open a Terminal, do

  dmesg > /tmp/dmesg.txt

and attach /tmp/dmesg.txt here? Thanks!

I reproduced the situation, and get the same error with beh:/1/0/120/socket:myprinter:9100. However, it does not cause an AppArmor error message in dmesg, and rightfully disabling apparmor does not fix the situation either.

The file path looks fishy, why does it try to put the temporary file into / ?

I also tried to fix the printer location to match the documentation: beh:/1/0/120/socket://myprinter:9100, however, that did not work either.

Presumably beh writes its temporary file into an invalid location (/ instead or /var/spool/cups/...). Till, how can I find out with which parameters it calls the beh backend? Can I put an strace in between to see which files it creates?

Till, maybe the problem is also that beh is run as user 'lp', not user 'root'? If it does need root, beh needs to be installed 744, not 755. It might be that this was the case previously, and thus the wrong temporary file path was just hidden.

Needs input from Till, reassigning.

It is a problem of CUPS. CUPS tells nicely in the error_log which environment variables it defines for the job, a total of 25, including TMPDIR.

If you add the following lines to /usr/lib/cups/filter/beh, near the beginning

use Data::Dumper;
print STDERR Dumper(%ENV);

You get listed all environment variables which beh can find, a total of 24, not including TMPDIR.

Ah, thanks TIll. Opening a task for foomatic-filters, because it really should have a sensible fallback if TMPDIR is not set (/tmp).

I'll examine the situation in cups.

This bug was fixed in the package foomatic-filters - 4.0.0~bzr171-0ubuntu1

---------------
foomatic-filters (4.0.0~bzr171-0ubuntu1) intrepid; urgency=low

  * New upstream release
     - Let the beh CUPS backend use /tmp as temporary directory when CUPS
       does not supply the $TMPDIR environment variable (LP: #268284).

 -- Till Kamppeter <email address hidden> Thu, 25 Sep 2008 09:28:44 +0200

For the CUPS task see also the upstream bug report

http://www.cups.org/str.php?L2962

(which was -- again -- prematurely closed as "apparmor problem", which is clearly wrong. AppArmor rightfully prevents cups from writing into /, but doesn't change anything in the environment.

The foomatic-filters fix presumably corrected this problem; closing the cups task as invalid. If this is incorrect, obviously, feel free to reopen. Thanks.

Sorry, clicked the wrong status (-: Thanks for fixing.